These files are part of the dataset "Historical built-up intensity layer series for the U.S. 1810 � 2015,"
contained in the dataverse �HISDAC-US: Historical Settlement Data Compilation for the United States� 
(https://dataverse.harvard.edu/dataverse/hisdacus).

Reference:
Ahn, Yoonjung;Leyk, Stefan;Uhl, Johannes H.; McShane, Caitlin M., 2023, "Gridded Settlement Data for the Conterminous United States Over 200 years",
https://doi.org/10.7910/DVN/1WB9E4, Harvard Dataverse

Related Publication:
Leyk, Stefan; Uhl, Johannes H., 2018, "HISDAC-US: Historical Settlement Data Compilation for the Conterminous United States Over 200 Years," Scientific Data 5:180175
https://doi.org/10.1038/sdata.2018.175
Uhl, J. H. et al. Fine-grained, spatio-temporal datasets measuring 200 years of land development in the United States. Earth Syst. Sci. Data 96�114 (2020). doi:10.4324/9781315019444-13

This dataset contains the following files:

- BUI.tar.gz: Archive contains the time series of BUI raster layers between 1810 and 2015 (BUI_1810 � BUI_2015) with semi-decadal temporal resolution.

Abbreviations and explanations:
BUI:		Built-up intensity. Integer-valued raster datasets containing indoor building gross area sum per pixel area in square feet.

Data source: 
- Zillow Transaction and Assessment Dataset (ZTRAX) (c) Zillow Inc.
- Parcel (c) Parcel Atlas
- BuildZero Open City Model
Spatial resolution: 250m

Spatial resolution: 250m
Coordinate reference system:
USA Contiguous Albers Equal Area Conic USGS version (EPSG:5070)
https://spatialreference.org/ref/sr-org/usa_contiguous_albers_equal_area_conic_usgs_version-2/
Proj4: +proj=aea +lat_1=29.5 +lat_2=45.5 +lat_0=23.0 +lon_0=-96 +x_0=0 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m +no_defs

Contact:
Stefan Leyk
Department of Geography
University of Colorado Boulder
GUGG 110, 260 UCB 
Boulder, CO 80309-0260, United States of America
stefan.leyk@colorado.edu